The Lower "T.e" Letter Stage is also known as T.e 1 to 4 (after Leupold & van der Vlerk 1931; T.e 5 being the Upper T.e of later workers) and is alsmost equivalent to the Late Oligocene series (c. 29 to 25 mybp). The four subdivisions of L. & vdV. fell into disuse by being impractical, but were redefined as T.e 1, T.e 2-3 and T.e 4 in an unpublished work on NE Java by Muhar (1956/57). This work of Muhar has recently been re-evaluated and integrated with planktonic stratigraphy and SIS age dates (unpublished), and a summary is given here: LARGER FORAM RANGE CHART- DETAILS FOR OLIGO-MIOCENE.
The images shown here are reduced to about 1/5 their original resolution and highly compressed as JPG files. Original images available on request, as TIF files from 120 to 400 MB in size
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- T.e 4: Latest Oligocene Limestone (780 KB). A large file that includes good examples of Tansinhokella as well as macrospheric and other Spiroclypeus. also in this image are early specimens of Miogypsinoides, with the juvenile Neorotalia mecatepecensis stage still visible. NE Java.
- T.e 2-3: Latest Oligocene Limestone (1.2 MB). A large file with good examples of flat-formed Tansinhokella as well as Eulepidina and Neorotalia mecatepecensis. NE Java. As with the H. (Vlerkina) borneensis mentioned below, the Tansinhokella specimens here can also be seen to contain paired inter-septal canals. A feature not yet observed in Late Eocene specimens of Tansinhokella
- T.e 2-3: Late Oligocene Limestone (464 KB). Not a very well preserved limestone as interbedded with mudstones and weathered, but both this thin section and the surrounding mudstones contain common Neorotalia mecatepecensis but an absence of the descendent Miogypsinoides, which is first seen slightly above this location. In the lower right corner are specimens of both Tansinhokella and H. (vlerkina) borneensis NE Java.
- T.e 2-3: Latest Oligocene Limestone (155 KB). A small image with good examples of early Tansinhokella with limited numbers of lateral chamberlets. Sample dated as 27 1/2 MYBP by SIS
- T.e 1 to 2-3 transition: early Late Oligocene Limestone (896 KB). This sample contains many H. (Vlerkina) borneensis specimens, no significant examples of "Heterostegina cf. depressa" Tan, and many Neorotalia mecatepecensis This argillaceous sample can be processed and yields specimens of H. (V.) borneensis where in the adult stages the first sign of subdivision of the alar prolongation can be seen (- in the lower of these 2 images; until this level there had been no such subdivision). Compare this to the later specimens from T.e2-3 where over the central umbonal area some complex and irregular shaped chamberlets have forms through this subdivision (specimen from mid-Rajamandala limestone west Java). Other markers from T.e1 to 2-3 transition include Austrotrillina striata (236 KB; Black dot is 100 microns) seen here with Borelis pygmaeus. The broad, widely spaced alveolae in the test wall contrast with the branched alveolae seen in T.f A. howchini.
- T.e 1: from the center of the Kujung anticline, just above T.d.. Another base Late Oligocene Limestone (368 KB). From Cicarucup West Java. Note the abundance of Heterostegina borneensis but absence of the descendent Tansinhokella. From just below this sample a slightly older sample (996 KB) contains only maturo-evolute "Heterostegina cf. depressa" Tan, the ancestral form to H. (Vlerkina) borneensis. Note that these Heterostegina forms have the same paired inter-septal canals as seen in Cycloclypeus. Both lineages are thought to have evolved from the same Planostegina stock in T.c. Such paired interseptal canals have not yet been observed in Late Eocene (T.b) Heterostegines, even in the well preserved Nanggulan samples
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